Light is electromagnetic waves which comprise an enormous range of frequencies and this continuous range of frequencies is known as the electromagnetic spectrum. Within the electromagnetic spectrum is the spectrum of visible light, which is a very narrow band of wavelengths located to the right of the infrared region and to the left of the ultraviolet region. Each individual wavelength within the spectrum of visible light wavelengths is representative of a particular color. That is, when light of that particular wavelength strikes the retina of our eye, we perceive that specific color sensation. For example, we see grass as green because grass absorbs all light frequencies of wavelength except green which it reflects back. Though electromagnetic waves exist in a vast range of wavelengths, our eyes are sensitive to only a very narrow band. Since this narrow band of wavelengths is the means by which humans see, we refer to it as the visible light spectrum and it was Isaac Newton that divided the light spectrum into seven named colors, Red, Orange, Yellow, Green, Blue, Indigo and Violet.
When all the wavelengths of the visible light spectrum strike your eye at the same time, white is perceived. The sensation of white is not the result of a single color of light. Rather, the sensation of white is the result of a mixture of two or more colors of light. Technically speaking, white is not a color at all, at least not in the sense that there is a light wave with a wavelength that is characteristic of white. Rather, white is the combination of all the colors of the visible light spectrum. If all the wavelengths of the visible light spectrum give the appearance of white, then none of the wavelengths would lead to the appearance of black. Once more, black is not actually a color. Technically speaking, black is merely the absence of the wavelengths of the visible light spectrum.
A red laser will pop all colors of a balloon except for red and white. A red laser does not pop a red balloon because the wavelength of the red laser matches the wavelength of the red balloon, thus the red laser simply reflects off the surface of the red balloon. White on the other hand, reflects the full light spectrum, thus all wavelengths of light reflect off a white balloon, therefore no color of laser will pop a white balloon.
Light has several optical properties of interest, especially relating to how light behaves at the boundary between mediums. Generally light is refracted or reflected at boundaries, and in some cases both phenomena occur. With the appropriate configurations, such refractions and reflections can be manipulated to internally illuminate physical bodies, such as components of a footwear. The internally illuminated effect is enhanced by providing for multiple refractions of light, which result in amplified brightness and intensity of observed light.
The present invention describes a number of applications based on twice-refracted light with regards to footwear. Twice-refracted light benefits a variety of footwear types, including both open footwear such as sandals and closed footwear such as boots. The twice-refracted light (resulting from internal refraction) is not only a new innovation for illuminated footwear, it also enhances additional visual features e.g. letters, logos, and further aesthetic designs.